Dry-dock



J. B. SIMPSON.

DRY DOCK.-

No. 12,034 Patented Dec. 5, 1854. I

her work.

UNITED STATES PATE T OFFICE.

JAMES E. SIMPSON, or EAST BosToN, MASSACHUSETTS.

DRY-DOCK.

Specification of Letters Patent No. 12,034, dated December 5, 1854.

To all whom it may concern 7 Be it known that I, JAMES E; SIMPSON, of East Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Permanent Dry-Docks and in the Method of Constructing the Same, of which the following is a full, clear, and exact description, reference being had to the annexed drawings, making part of this specification, in which Figure 1 is a plan of the dock. Fig. 2, a longitudinal section through the center of the same. Fig. 3 a front endview of the dock. Fig. 4 a transverse section upon the line A, A, of Fig. 1. Fig. 5, a section upon the line B, B, of Fig. 1. i

Permanent dry docks have heretofore been constructed of cut stone masonry, laid either upon a natural foundation or upon an artificial one composed of piling and tim- In the former case there is nothing to prevent the water from finding its way beneath the masonry of the dock, and upon the slightest displacement of the stones of the floor; the dock leaks and ultimate-1y the foundation beneath is impaired by the flow of the water. In the case where the masonry is laid upon a foundation of piling and timber, .it is found impossible to obtain a floor capable of supporting a heavy partial strain, orone that can safely be trusted with a vessel that is much hogged, as the great weight which is thus brought upon certain points, causes those points to yield, and thus the integrity of the floor 1S impaired.

To produce a dock that shall be free from these defects and at the same time to reduce the cost of these Structures, is the object of my present invention, and my invention consists in making use of the natural clay foundation for the floor of the dock, the sldes and back end being formed of piles, the puddling between the inner and outer piling resting upon the clay floor, and forming a continuation of it after the manner in which cofi'erdams are puddled; the front end of the dock through which the vessels are admitted being occupied by the gates.

To enable others skilled in the art to make and use my invention I will proceed to describe the manner in which I have carried it out.

A spot is selected for the locality of the dock where a clay foundation at the requisite depthmay be found :This may be upon the bank or within the river ;'in either case the water is to be excluded from the vicinity of the operations by cofi'erdams pumplng, &c., previous to commencing wlth the dock itself. The earth, mud, or whatever else may overlie the natural clay stratum, is then to be cleaned off down to the depth required :-Into this clay, represented by C, in the drawings, the inner and outer rows of piles a a, are then driven;

- these piles are stayed by the diagonal braces 71. is another set of sleepers which strut between the piles a. and are sunk slightly-beneath the level of the sleepers f, and into the surface of the foundation clay; these latter sleepers are secured firmly to the piles, and are braced in the most substantial manner by the knees i.

The space D inclosed between the rows of piles, is filled with puddling clay, resting directly upon the surface of the natural clay stratum, which is cleaned offfor the purpose of receiving it. This puddling thus forms a continuation of the floor of the dock, without interruption or crevice between them.

m is a gutter through the center of the dock, in which any leakage which maytake place finds its way to the pumps in the engine house at E, the latter being erected over an extension of the piling made for the purpose at the entrance.

For the purpose of forming abutment-s to resist the thrust of the gates, square piles are driven as seen at 'H, .in contact with each other, the space inclosed by them being also filled with clay, which like that in the sides of the dock, rests upon and forms a continuation of the foundation; this piling is braced in the most substantial manner by knees n, Fig. 1, and is otherwise made as solid and unyielding as possible. To these abutments the gates F,.G, are hinged.

For the purpose of preventing the water from making its way. beneath the gates the latter are made to shut against the tops of a. row of sheet piling P, driven into the clay as seen in Fig. 3, immediately within the bottom of the gate ;0 are ways upon which the rollers which support the gates run in the customary manner.

The space R, within the body of the dock not being required to be left vacant, is filled with clay as seen in the drawings, and serves still further to strengthen the sides of the dock against the lateral thrust.

The advantages which a dock constructed upon this principle possesses over all other: heretofore constructed are many; a few of these advantages may be enumerated as follows: 1st. The original cost is less than onetenth of that required for a permanent stone dock. 2nd. No partial strain upon any part of the floor of the dock can possibly result in injury to the structure, as the whole weight is borne by the natural stratum, and it matters not where or to what extent this weight be imposed upon the floor of the clock. This characteristic renders my dock capable of accommodating vessels which are badly hogged, and that would be in consequence refused admittance into any other docks. 3d. My dock is far more comfortable to the workmen than a stone dock which remains for a long time cold and damp after it is emptied of water.

I do not claim constructing a cofi'erdam by driving double rows of piles, and filling the interspace with clay, but

What I do claim as my invention and desire to secure by Letters Patent is The method herein described of constructing dry docks by making use of the natural stratum of clay for the floor of the dock, and continuing the same up through the walls by means of puddling, in the manner setforth; the front of the dock being furnished with gates for the admission of the vessel as described.

JAMES E. SIMPSON. Witnesses:

M. H. MERRIAM, J. B. CROSBY. 

